abstract class People {
    constructor(public name: string) { }
    abstract printName(): void;
}
class Man extends People {
    constructor(name: string) {
        super(name);
        this.name = name;
    }
    printName() {
        console.log(this.name);
    }
}
const m = new Man(); // error 应有 1 个参数，但获得 0 个
const man = new Man("lison");
man.printName(); // 'lison'
const p = new People("lison"); // error 无法创建抽象类的实例